#include<iostream>
#include<stdio.h> 
#include<stdlib.h>
#include<string.h>
#include<algorithm>
#include<cmath>
using namespace std;

int main()
{    char s[210];   
  while(cin>>s){       
  sort(s+0,s+strlen(s));        
  cout<<s<<endl;    }       
  return 0;
}
